Container



March 30, 1943. I; o. HILL :ETAL

CONTAINER Filed Sept. 19, 1941 Patented Mar. 30, 1943 Lyle o.

assignors mu and Leland w. Short, Chicago, 111., to The American Dairy Cattle Club,

Chicago, 111., a corporation of Illinois Application September 19, 1941, Serial No. 411,462

Claims.

This invention relates to a container and has for an object the provision of a container or receptacle useful for shipping materials at a substantially constant predetermined temperature.

In the transportation or shipping of physiological specimens and certain other materials, it

is desirable and often necessary that they be maintained at a substantially constant temperature during shipment. This is particularly desirable for physiological specimens or materials which are subject to bacteriological or enzymatic degradation at ordinary temperatures and which may be adversely affected at or near freezing temperatures. Examples of such materials which are desired to be maintained at substantially constant temperatures during shipment are: semen for breeding purposes,'vaccines, bacteriological specimens, certain enzyme preparations, laboratory tissue cultures and the like.

Due to the extreme sensitivity of certain physiological materials such as those that have been indicated above, it has been necessary to ship them in refrigerator cars or other large cabinets in which the temperature can be thermostatically controlled. If the material is permitted to become too warm it may be adversely afiected by bacteriological or enzymatic action. On the other hand, if the temperature is allowed to drop below a predetermined point, the physiological activity of the material may be impaired. The

problem has been particularly acute in the transportation and shipment of animal semen which is employed for breeding purposes.

In recent years the artificial insemination of animals has become common practice. It is often desirable that the insemination be carried out at a remote distance from the place of origin of the semen, Semen is very sensitive to temperature. If maintained at a temperature between about 32 and 50 however, it may be kept for an indefinite period up to several weeks. The sperm within the semen has a tendency to dierapidly at temperatures substantially above 50 F. or below 32 F. It is therefore necessary when these materials are transportedfor any distance to maintain them at a temperature range within the above indicated limits which is least harmful to the sperm.

When transporting the material for very long distances,'such as from the United States to Australia or the Argentine, it is necessary and practicable to ship the material in temperatureregulated cold boxes or refrigerators. It is impractical, however, to transport'small amounts of such materials for relatively short distances in refrigerators or other temperature regulated containers because of the expense involved. The problem becomes particularly acute when the material is sent from the point of origin or point of distribution to individual farms or ranches where the semen is actually used for the artificial insemination. I

It is therefore one object of this invention to provide a container for packaging and shipping physiological specimens within a predetermined temperature range which may be maintained for an indefinite period of time.

A further object of this invention is to provide a shipping container for physiological specimens, particularly animal semen, which container is compact and comprises means for closely controlling the temperature of the contentsof the receptacle.

A further object of this invention is to provide a durable container which may be used to ship physiological specimens under practically any normal shipping condition without risk of breakage of the container.

Further and additional objects 'will appear from the following description, the accompanying drawing and the appended claims.

In accordance with one embodiment got this invention, the container comprises a vacuum bottle having contained therein a liquid or solid substance having a melting temperature which remains substantially constant or varies only within relatively narrow limits throughout the depending upon the particular substance employed, the particular temperature desired, and

- the conditions under which the container is stored or shipped. A particular feature of the invention is the provision of an all-metal container which is so constructed that it may be subjected during shipping without the danger of breakage. The inner receptacle within the vacuum bottle is secured in such a manner as to provide a seal for the fusible material whereby leakage thereof from the bottle is normally prevented. Furthermore, the inner receptacle is integrated with the vacuum bottle only adjacent the inner shell to all conditions normally encountered.

- ods of use.

thereof in order to prevent excessive heat transfer into or out of the bottle during normal peri- This last mentioned feature of the present construction has been found to be particularly important since the length of time at which the material may be maintained at a constant temperature within the receptacle is thereby increased as much as 200% or 300%.

For a more complete understanding of this invention, reference will now be had to the drawing in which Figure 1 shows an elevatlonal sectional view of a container constructed in accordance with one embodiment of this invention.

The container comprises a metal outer shell H! which may be of heavy stainless steel or other metal which is sufiiciently heavy to permit a vacuum to be drawn thereonand which is resistant to any jars or knocks that the container might suffer during normal shipping. The outer shell l has an inwardly extending funnel-shaped tubular member l4 adjacent the upper portion thereof which member is integral with the outer shell and an inner shell l2. The funnel-shaped tubular member It supports the inner shell ii in spaced relationship to the outer shell I0 whereby a space is positioned between the shells which is capable of being evacuated. The funnel-shaped tubular member l4 and the inner shellare preferably made of a corrosion-resisting material such as stainless steel. A hermetically sealed seam I6 is provided in the upper portion of the inner shell l2 and hermetically sealed seams l8 and 20 are provided in the upper and lower portions of the outer shell I. These seams are formed when the vacuum bottle is assembled. The bottom of the outer shell is provided with a valve plug 22 inserted through an opening 24 which may be employed for exhausting air or other gases from the space 26 between the outer shell l0 and the inner shell l2. A false bottom 25 is positioned in the lower portion of the outer shell Ill for rein forcing the shell after a vacuum has been obtained therein. Apertures 21 in the false bottom provide passageways for the gas exhausted from the space 26 to the opening 24. A protective casing 28 is provided for the valve plug 22 and serves as a suitable base for the container.

The inner shell I2 is substantially filled with a ture within those limits at which it is desired to maintain the physiological specimen within the container. This fusible substance may be either a pure chemical compound or it may be'a mixture of two or more compounds, such mixture preferably being a eutectic mixture of one type or another. -A large number of compounds are available for use as will be hereinafter more fully described. t

. As a means for holding the physiological specimen within the container and as a means for sealing the fusible substance within the inner shell l2, an inner cylindrical receptacle is provided having a cylindrical main body portion 30 and a slightly outwardly flared upper portion 32 for tightly engaging that portion of the funnelshaped tubular member ll adjacent its juncture with the inner shell II. .The upper walls 32 of this inner receptacle are integrated with the tubular member "by soldering or welding. The receptacle provides a means for holding a specimen in a glass phial or test tube (not shown) in heat exchange relationship with the fusible substance. in the inner shell l2. Cotton wadding 34 may be inserted into the bottom of the receptacle 30 in I fusible substance which has a melting temperaorder to cushion the glass test tube or phial which may carry the'desired specimen. It is important that the upper portion 32 of the inner receptacle 3!] be secured to a portion of the vacuum bottle removed from the outer shell in order to prevent excessive heat transfer into or out of the container.

In order to retain the specimen-containing tube (not shown) within the inner receptable 30, a cork stopper 3B is provided which fits into the tubular member It. A cap 38 may be threadably secured to a collar 4!] integrated with the upper portion of the container to protect the top of the stopper 36.

In the normal use of the hereinbefore described container for the transportation of animal semen, the cap and stopper are first removed and the entire container is subjected to refrigerating conditions. The refrigerating condition is maintained for a period sufficient to permit substantially all of the fluid contained within the inner receptacle H to solidify. After solidification has occurred, the container is heated or subjected to ordinary room temperatures until the solidified substance within the inner shell has justbegun constant or reaches the temperature which corresponds to the melting point of the fluid contained within the inner shell. At this time the container is ready for use and the semen which may be contained within a glass test tube or phial is inserted into the inner receptacle 30 and if desired may be packed therein with cotton wadding. The stopper 36 is inserted into the tubular member I4 and the metal cap 38 i screwed onto the top of the container over the stopper 38. The receptacle containing the semen is now ready for shipment or storage under temperature conditions which are normally higher than that temperature which is optimum for the preservation of the semen within the inner receptacle 30. The vacuum chamber surrounding the inner shell l2 prevents the rapid diffusion of heat thereinto from the surrounding atmosphere and melting of the solidified substance is thereby substantially inhibited. Moreover, the heat that is transferred into the inner shell is used up in melting the solidified substance and the temperature within the container therefore remains substantially constant until such substance has been entirely melted, the heat being absorbed corresponding to the latent heat of fusion of the substance. It is important that the inner receptacle be secured to the container adjacent the inner shell I! and t not be exposed to the outer portions of the container for the reason that the transfer of heat by means of the walls of the inner receptacle into the interior of the inner shell is thereby inhibited.

Numerous tests have been made employing receptacles which are made in the manner described above. In a receptacle in which the inner shell has the capacity of about one quart, it has been found possible to maintain a specimen of bull semen at a constant refrigerating temperature between about 34 and 48 F. for a period of 24 to 48 hours or longer even when the container itself was subjected to room temperatures around about F. or higher. The container of this invention, being entirely constructed of metal, is very able and may be shipped by mail or parcel post without risk of breakage. The physiological specimen contained within the receptacle will be preserved against deterioration by heat, thereby permens to distant points without the necessity of providing complex thermostatically controlled refrigerating units.

It will be seen from the above description and the accompanying drawing that a compact container has been provided which is useful for the purposes above indicated, i. e., maintaining small amounts of physiological materials or other substances at constant temperatures during shipping. The container may also have other uses than those indicated above, In certain cases it may be desirable to transport small quantities of certain chemical reagents or botanical or zoological specimens under conditions of controlled temperature. The container that is herein described may be employed for these purposes.

It will, of course; be evident that any predetermined temperature may be selected by a proper selection of the fluid that is enclosed within the inner shell of the container. The effectiveness of the liquid employed will depend to a large degree on its melting point, its latent heat capacity, and slowconductivity. A large variety of pure chemical substances may be used. If desired. a mixture of chemicals may be used whereby a desired melting point may be artifically produced, certain eutectic mixtures being ,particularly useful. For preserving the specimen at a temperature lower than ordinary room temperatures, the following substances may be used if, desired: acetic acid (melting point 62.1 R), bromoform (melting point=48.2 F.) formic acid melting point=47.5 E), or benzene (melting point- 41.? F). Small bits of glass or other material may be added to eliminate the supercooling effect.

In accordance with one embodiment of this invention, it is possible to keep certain specimens at temperatures somewhat above ordinary room temperature for. the period of time when they are being shipped. In such a case, it is necessary to provide a substance in the inner shell which normally solidifies or melts above room temperatures and at that temperature corresponding to which it is desired that the speciment be maintained. In such a case, the container is first heated to convert the fusible substance to the liquid state, then cooled until it just begins to solidify. At this time the specimen is -introduced into the receptacle and the whole is packaged into the container and im-' mediately shipped. The vacuum surrounding the substance inhibits the dissipation of the latent heat of fusion and the temperature of the speciment will be maintained constant until the entire mass has solidified. This period will also depend upon the temperature differential and the latent heat of fusion of the solidifying mass. Suitable chemical compounds that may be used as a fluid under these conditions are: capric acid (melting point=88.3 F.) dibromacetic acid (melting point:118 4 'F.), dimethyl tartrate (melting point-:118.4 F.), cetyl alcohol (melting point: 122.0 F), and arachidic' acid (melting point: l'70.6 F.)

In case the specimen to be shipped should be kept at very near room temperature, and it is desirable to insure that it will be so kept during shipment, a substance is selected having a desired melting point around room temperature.

It is then only. partially solidified before the specimen is introduced and the container packed for immediate shipment. The temperature of the specimen will remain substantially constant regardless of temporary temperature fluctuations to which the container may be subjected during shipment or storage. I

Other factors that become of importance in the selection of a suitable fiuid or fusible material are cost, infiammability, toxicity, corrosive power, coefficient of expansion on solidification, and the like.

Important practical considerations should be taken into account in the construction of a container in accordance with the teachings of the present invention. It is desirable that the entire container be small and easily handled. It should be light in weight so that shipping costs will not be excessive or prohibitive. It should contain sufficient fluid to maintain the specimen at the proper temperature for the desired length of time, such time under ordinary conditions being from about 24 to about '72 hours, or even longer. I I The desideratumis to obtain a maximum heat insulating effect with decreased weight and bulk and an increased time during which the enclosed specimen will be maintained at the desired constant temperature. The container of this invention satisfies the above indicated requisites and in addition it is readily made, easily used, and is strong and durable.

It will be-apparent from the above considerations that a variety of modifications are permissible without departing from the spirit and scope of the present invention. For example, the volume of fluid substance surrounding the specimen may be increased or decreased to any reasonable extent. The comparative capacity of the fluid container preferably may be considerably-greater than the'specimen receptacle immersed or submerged therein. The duration of time that the specimen is to remain in the container at a constant temperature may be greatly increased by increasing the amount of the fluid capacity of the chamber. vacuum bottle and inner receptacle may be made of a plastiematerial. strong and durable and capable of supporting a vacuum without danger of breakage. Also additional heat insulation may be applied to the outer surfaces of the container.

awhile a particular embodiment of this invention is shown above, it will be understood, of course, that the invention is not to be limited thereto, since many modifications may be made, and it is contemplated, therefore. by the appended claims, to cover any such modifications as fall within the true, spirit and scope of this invention.

We claim:

1. A container for preserving a biological specimen within a predetermined temperature range for an indefinite period which comprises an outer metal shell, an inner metal shell spaced therefrom, a metal tubular member extending inwardly of said outer shell and integral therewith for supporting the inner shell within the outer. shell, said inner shell and said outer shell being hermetically sealed to said tubular member whereby a vacuum may be maintained in the space therebetween, an inner specimen receptacle extending into said inner shell accessible through said tubular member and integrated therewith, and a substance substantially filling said inner shell and sealed therewithin by said receptacle, said sub-,- stance having a-melting temperature which remains within said range throughout the period of the change of state of said substance.

2. A container for shipping a biological speci- Also, if desired, the

Such material should be,

men at a temperature within a predetermined temperature range which comprises an outer metal shell, an inner metal shell spaced therefrom, a metal tubular member extending inwardly of said outer shell and integral therewith for supporting the inner shell within the outer shell, said inner shell and said outer shell bein hermetically sealed to said tubular member whereby a vacuum may bemaintained in the space therebetween, an inner specimen receptacle extending into said inner shell accessible through said tubular member and integrated,

therewith, a closure member associated with said tubular member for retaining said specimen within said receptacle, and a heat exchange material substantially filling said inner shell and sealed therewithin by said receptacle, said material having a melting point within said temperature range at which it is desired to maintain said specimen.

3. A container for shipping a biological specimen at a temperature within a predetermined temperature range which comprises an outer metal shell, an inner metal shell spaced therefrom, a metal tubular member extending inwardly of said outer shell and integral therewith for supporting the inner shell within the outer shell, said inner shell and said outer shell being hermetically sealed to said tubular member whereby a vacuum may be maintained in the space therebetween, an inner specimen receptacle extending into said inner shell and accessible through said tubular member and integrated therewith at a point removed from said outer shell but adjacent said inner shell, a removable stopper inserted in said tubular member for retaining said specimen within said receptacle, and a heat exchange material substantially filling said inner shell and sealed therein by said receptacle, said material having a melting point within said temperature range at which it is desired to maintain said specimen.

4. A container for shipping a biological specimen at a temperature within a predetermined temperature range which comprises an outer metal shell, an inner metal shell spaced therefrom, a funnel-shaped metal tubular member extending inwardly of said outer shell and integral therewith for supporting the inner shell-within the outer'shll, said inner shell and said outer shell being hermetically sealed to said tubular member whereby a vacuum may be maintained per inserted in said tubular member for retaining said specimen within said receptacle, and a heat exchange material substantially filling said inner shell and sealed therein by said receptacle, said material surrounding said receptacle and having a melting point within said temperature range at which it is desired to maintain said specimen.

5. A container for preserving a specimen within a predetermined temperature range for an indefinite period which comprises an outer shell, an inner shell spaced therefrom, a tubular member extending inwardly of said outer shell for supporting the inner shell within the outer shell, said inner shell and said outer shell being hermetically sealed to said tubular member whereby a vacuum may be maintained in the space therebetween, an inner specimen receptacle extending into said inner shell sealed to said tubular member and accessible therethrough, and a substance contained within said inner shell and sealed therewithin by said receptacle, said substance having a melting temperature which remains within said range throughout the period of change of state of said substance.

. LYLE O. HILL.

LELAND W. SHORT. 

